CAPE CANAVERAL, Fla. — NASA this morning aborted a spacewalk at the International Space Station because of a dangerous water leak in an astronaut’s helmet that drenched his eyes, nose and mouth. “It’s a lot of water,” Italy’s first spacewalker, Luca Parmitano, reported once he was back in the air lock of the International Space Station. The leak was so bad that Parmitano asked his spacewalking partner, American Christopher Cassidy, to help him back in. The trouble cropped up barely an hour into what was to be a six-hour spacewalk to perform cable work and other routine maintenance. It was the astronauts’ second spacewalk in eight days. Parmitano startled everyone when he announced that he felt a lot of water on the back of his head. At first, he thought it was sweat because of all his exertion on the job. But he was repeatedly assured it was not sweat. Cassidy said it might be water from his drink bag; it looked like a half-liter of water had leaked out. The water eventually got into Parmitano’s eyes. That’s when NASA ordered the two men back inside. Then the water drenched his nose and mouth, and he had trouble hearing on the radio lines. Parmitano could not speak because of all the water. “He looks fine,” Cassidy assured everyone. “He looks miserable. But OK.”